Sheaths are employed in a wide variety of medical procedures. For example, sheaths may be utilized when performing vascular procedures, genitourinary track procedures, gastrointestinal tract procedures, and the like. For example, individuals with renal failure require some form of hemofiltration in order to survive. The vast majority of these patients survive through hemodialysis. Most of these patients receive their hemodialysis through permanent, high flow, vascular conduits, created surgically in their extremities. Over time, these conduits can stop functioning adequately. One of the key elements of survival in this patient population is maintenance of adequate vascular access and function of these vascular conduits. In order to achieve this, the conduits require repair and maintenance throughout their lifespan. These repairs are usually performed in an interventional radiology suite, cardiology suite, and/or operating room by percutaneous (access from skin to conduit without large incision) technique. Sheaths are minimally invasive interventional tools used in such techniques.
Sheaths comprise temporary, external, conduit extensions that facilitate repair of the internal, permanent conduit from the inside. These conduit extensions communicate most commonly through the vascular system, but also can act as conduits between the external environment and any internal plumbing system, e.g. arterial, venous, biliary, portal venous, gastrointestinal tract, renal collecting system, excluded aortic aneurysm sac, central canal/thecal sac/epidural space. In this way, large incisions are avoided, recovery is quicker, treatment is less expensive versus surgery, and the life span of the veins and arteries used is prolonged. Generally, one to two sheaths are employed during each intervention.